The methods of evaluating tolerance levels of plants to stressors for many years have been based on indices and visual based scores which are more of descriptive and qualitative. Despite their ease of use the strategies have demonstrated errors arising from different researchers levels of perception and biases in judgment. This has resulted to inaccuracies in the generated data leading to poor monitoring and forecasting of plant stresses, especially in plant tolerance evaluations against diseases. Moreover, these techniques have been limited to the observation of one if not a few parameters separately, ignoring the complexity and dynamics of plant responses to stressors which in many cases affects different parameters of the plant variably. Despite, the development of computer imaging systems, the problem of cost and availability for developing countries is a challenge. Therefore, the objective of this study was to develop a cheap quantitative host plant tolerance levels estimation technique which is based on logarithmic efficacy indices generation and a table that can be used to predict their corresponding percentages that incorporates a novel concept known as IPLI (Integrated Parameter Logarithmic Indexing). The strategy integrates three parameters that are affected by stress significantly and generates holistic indices whose corresponding percentages estimate tolerance levels. Napier stunt disease infected napier grass treatments of accession 16789 and Bana variety were used to demonstrate how the technique works. Basing on the preliminary results their tolerance levels were estimated at 29.86% and 12.59% respectively. The approach looks promising in quantitative evaluation of the trait.